RUNS THEN WILL CRANK NOT START THEN RUN FINE A FEW HOURS LATER

1996 Ford Explorer • 219,000 miles

1996 ford explorer 4.0L V6 pushrod engine. I am pretty sure it is the cam sensor but since this seems to require pulling the intake I want to be sure. The fuel pump will stop running and the vehicle will die then a few hours later it will start right up only to die again shortly to a few days later. I have ran an OBD2 scan with no codes. I have pulled the pump, since this is what I originally thought was wrong the first time it happened put power to it and it ran fine so I reistalled it and the vehicle fired right up then died again a few days later.